Add generics.py, result_display generic, first impl is LSString result printer

IPython/generics.py

@@ -0,0 +1,28 b''
+from IPython.ipapi import TryNext
+from IPython.external.simplegeneric import generic
+
+""" 'Generic' functions for extending IPython
+
+See http://cheeseshop.python.org/pypi/simplegeneric
+
+Here's an example from genutils.py:
+
+    def print_lsstring(arg):
+        """ Prettier (non-repr-like) and more informative printer for LSString """
+        print "LSString (.p, .n, .l, .s available). Value:"
+        print arg
+        
+    print_lsstring = result_display.when_type(LSString)(print_lsstring)
+
+(Yes, the nasty syntax is for python 2.3 compatibility. Your own extensions
+can use the niftier decorator syntax)
+
+"""
+
+@generic
+def result_display(result):
+    """ print the result of computation """
+    raise TryNext
+
+result_display = generic(result_display)
+

IPython/Prompts.py

@@ -2,7 +2,7 b''
 """
 Classes for handling input/output prompts.
 
-$Id: Prompts.py 2349 2007-05-15 16:20:35Z vivainio $"""
+$Id: Prompts.py 2397 2007-05-26 10:06:26Z vivainio $"""
 
 #*****************************************************************************
 #       Copyright (C) 2001-2006 Fernando Perez <[e-mail]>
@@ -30,6 +30,7 b' from IPython.Itpl import ItplNS'
 from IPython.ipstruct import Struct
 from IPython.macro import Macro
 from IPython.genutils import *
+from IPython.ipapi import TryNext
 
 #****************************************************************************
 #Color schemes for Prompts.
@@ -536,7 +537,9 b' class CachedOutput:'
         Do ip.set_hook("result_display", my_displayhook) for custom result
         display, e.g. when your own objects need special formatting.
         """
-
+        try:
+            return IPython.generics.result_display(arg)
+        except TryNext:            
         return self.shell.hooks.result_display(arg)
 
     # Assign the default display method:

IPython/genutils.py

@@ -5,7 +5,7 b' General purpose utilities.'
 This is a grab-bag of stuff I find useful in most programs I write. Some of
 these things are also convenient when working at the command line.
 
-$Id: genutils.py 2371 2007-05-23 18:40:26Z vivainio $"""
+$Id: genutils.py 2397 2007-05-26 10:06:26Z vivainio $"""
 
 #*****************************************************************************
 #       Copyright (C) 2001-2006 Fernando Perez. <[e-mail]>
@@ -36,6 +36,7 b' import warnings'
 import IPython
 from IPython.Itpl import Itpl,itpl,printpl
 from IPython import DPyGetOpt
+from IPython.generics import result_display
 from path import path
 if os.name == "nt":
     from IPython.winconsole import get_console_size
@@ -872,6 +873,7 b' class LSString(str):'
         .l (or .list) : value as list (split on newlines).
         .n (or .nlstr): original value (the string itself).
         .s (or .spstr): value as whitespace-separated string.
+        .p (or .paths): list of path objects
         
     Any values which require transformations are computed only once and
     cached.
@@ -912,6 +914,14 b' class LSString(str):'
     p = paths = property(get_paths)
 
 
+
+def print_lsstring(arg):
+    """ Prettier (non-repr-like) and more informative printer for LSString """
+    print "LSString (.p, .n, .l, .s available). Value:"
+    print arg
+    
+print_lsstring = result_display.when_type(LSString)(print_lsstring)
+
 #----------------------------------------------------------------------------
 class SList(list):
     """List derivative with a special access attributes.
@@ -921,6 +931,7 b' class SList(list):'
         .l (or .list) : value as list (the list itself).
         .n (or .nlstr): value as a string, joined on newlines.
         .s (or .spstr): value as a string, joined on spaces.
+        .p (or .paths): list of path objects
 
     Any values which require transformations are computed only once and
     cached."""